High-strength pure liquid plugging agent plugging technology for plugging leakage layer and plugging water

Abstract

The invention discloses a high-strength pure liquid plugging agent plugging technology for plugging a leakage layer and plugging water. The plugging technology includes the following steps that trailsqueezing is conducted on a to-be-plugged section, water injectivity indexes are tested, the using quantity of a plugging agent is calculated, a drillable composite bridge plug is set at the position30 meters below the to-be-plugged section, and then sand filling is carried out to the lower side of the plugged section; an oil pipe is tripped into the to-be-plugged section, a pipe column is squeezed, the plugging agent is prepared and further contains a silicone modified epoxy compound and a curing agent, the curing agent refers to tert-butyl peroxybenzoate or benzoyl peroxide peroxide, the plugging agent is squeezed into the plugged section, and a plugging agent plug is additionally arranged; and pressure shut-in waiting solidification is conducted, pressure testing is performed on the plugged plug surface, the plugging agent plug is removed in a drilling mode when pressure testing is qualified, plugging operation ending is confirmed after the pressure testing is qualified, the plugging agent with the silicone modified epoxy compound and the curing agent being mixed is used, the plugging strength can be improved and long-time plugging effectiveness is guaranteed.

Description

technical field [0001] The invention relates to the field of oil well plugging in oil fields, in particular to a high-strength pure liquid plugging agent plugging process for plugging leakage layers and water plugging. Background technique [0002] Domestic oilfields are mostly sandstone reservoirs and old oilfields developed by high-pressure water injection. Among them, water injection, heavy oil thermal recovery, acidification and other measures are the main types of measures in this old oilfield. In recent years, with the increase in the number of wells with casing damage, the downhole technology status The continuous deterioration and the increase of out-of-control reserves have seriously affected the stable production foundation of old oilfields. The existence of casing damage has led to more than 100 million tons of out-of-control geological reserves per year, destroying the perfection of well patterns and affecting the development effect of water flooding oilfields. Ca...

AI Technical Summary

Problems solved by technology

[0002] Domestic oilfields are mostly sandstone reservoirs and old oilfields developed by high-pressure water injection. Among them, water injection, heavy oil thermal recovery, acidification and other measures are the main types of measures in this old oilfield. In recent years, with the increase in the number of wells with casing damage, the downhole technology status The continuous deterioration and the increase of out-of-control reserves have seriously affected the stable production foundation of old oilfields. The existence of casing damage has led to more than 100 million tons of out-of-control geological reserves per year, destroying the perfection of well patterns and affecting the development effect of water flooding oilfields. Casing subsidies The process of repairing damaged wells with expansion tubes has achieved good treatment effects in major oilfields. With the implementation of high-intensity water injection, layer modification acidification, and reservoir fracturing in the late stage of oilfield development, this part of the old wells repaired by subsidies and expansion tubes Due to the casing necking problem, such measures cannot be implemented again, which will lead to the shutdown of oil and water wells. The conventional plugging and water plugging use cement system or gel system, and the pressure test strength after plugging is only 8-10MPa , the validity period is only 3-5 months, and repeated plugging is required after the plugging fails, which not only causes economic losses, but also delays the production time of oil and gas wells, and the success rate of plugging is only about 30%. Therefore, a kind of High temperature resistant, high strength plugging technology has a very urgent demand in oilfields